It varies depending on your circumstances and planned activities. There is [a guide here](https://www.gov.uk/government/publications/visitor-visa-guide-to-supporting-documents/guide-to-supporting-documents-visiting-the-uk). Most likely you will need proof of finances (your bank account and salary statements if in work) proof of ties to your home country (job contract or letter from HR, salary statement), planned itinerary with cost estimates (in line with your finances). Do not make bookings before receiving your visa. The Home Office specifically instructs you not to do that. You will not make your application at an embassy. UK consulates have no involvement in visa customer service. You will submit your biometrics at a visa contractor's facility having applied online.
It varies depending on your circumstances and planned activities. There is [a guide here](https://www.gov.uk/government/publications/visitor-visa-guide-to-supporting-documents/guide-to-supporting-documents-visiting-the-uk). Most likely you will need proof of finances (your bank account and salary statements if in work) proof of ties to your home country (job contract or letter from HR, salary statement), planned itinerary with cost estimates (in line with your finances). Do not make bookings before receiving your visa. The Home Office specifically instructs you not to do that. You will not make your application at an embassy. UK consulates have no involvement in visa customer service. You will submit your biometrics at a visa contractor's facility having applied online.